 #include <stdio.h>
 #include <gsl/gsl_rng.h>
 #include <gsl/gsl_randist.h>
 
 int
 main (void)
 {
   const gsl_rng_type * T;
   gsl_rng * r;
 
   int i, n = 10;
   double mu = 3.0;
 
   /* create a generator chosen by the 
      environment variable GSL_RNG_TYPE */
 
   gsl_rng_env_setup();
 
   T = gsl_rng_default;
   r = gsl_rng_alloc (T);
 
   /* print n random variates chosen from 
      the poisson distribution with mean 
      parameter mu */
 
   for (i = 0; i < n; i++) 
     {
       unsigned int k = gsl_ran_poisson (r, mu);
       printf (" %u", k);
     }
 
   printf ("\n");
   gsl_rng_free (r);
   system("pause");
   return 0;
 }
